RFR - 8190482: InnocuousThread creation should not require the caller to possess enableContextClassLoaderOverride

[Roger Riggs]

Hi Chris,

Looks fine

Roger


On 11/5/2017 5:02 AM, Chris Hegarty wrote:
> Currently JDK code that wants to create innocuous threads is required to do so within a privileged context that has the "enableContextClassLoaderOverride" RuntimePermission ( since the InnocuousThread class overrides setContextClassLoader ). This permissions should not be required, especially if code in de-privileged modules wants to create innocuous threads.
>
> The factory methods for creating innocuous threads should assert privileges before constructing the thread.
>
> diff --git a/src/java.base/share/classes/jdk/internal/misc/InnocuousThread.java b/src/java.base/share/classes/jdk/internal/misc/InnocuousThread.java
> --- a/src/java.base/share/classes/jdk/internal/misc/InnocuousThread.java
> +++ b/src/java.base/share/classes/jdk/internal/misc/InnocuousThread.java
> @@ -62,10 +62,16 @@
>        * set to the system class loader.
>        */
>       public static Thread newThread(String name, Runnable target) {
> -        return new InnocuousThread(INNOCUOUSTHREADGROUP,
> -                                   target,
> -                                   name,
> -                                   ClassLoader.getSystemClassLoader());
> +        return AccessController.doPrivileged(
> +                new PrivilegedAction<Thread>() {
> +                    @Override
> +                    public Thread run() {
> +                        return new InnocuousThread(INNOCUOUSTHREADGROUP,
> +                                                   target,
> +                                                   name,
> +                                                   ClassLoader.getSystemClassLoader());
> +                    }
> +                });
>       }
>   
>       /**
> @@ -80,8 +86,14 @@
>        * Returns a new InnocuousThread with null context class loader.
>        */
>       public static Thread newSystemThread(String name, Runnable target) {
> -        return new InnocuousThread(INNOCUOUSTHREADGROUP,
> -                                   target, name, null);
> +        return AccessController.doPrivileged(
> +                new PrivilegedAction<Thread>() {
> +                    @Override
> +                    public Thread run() {
> +                        return new InnocuousThread(INNOCUOUSTHREADGROUP,
> +                                                   target, name, null);
> +                    }
> +                });
>       }
>   
> -Chris.